Vapor Pressure: Drinking BirdA novelty store "Drinking Bird" repeatedly dips is beak into a beaker of water and then bobs back to an upright position. Visible movement of a liquid in the bird's body accompanies the bobbing; the movement is caused by changing vapor pressure of the liquid due to different temperatures at the bird's head and the bird's body.

Liquids |

Phases / Phase Transitions / Diagrams

Sodium Chloride Crystal CleavageA knife is placed on a large sodium chloride crystal parallel to a cleavage plane. When the knife is tapped, the crystal breaks cleanly, creating two smaller crystals.

Paramagnetism: Nitrogen and OxygenA magnet is shown to strongly attract a pair of metal tongs. The magnet has no visible effect on liquid nitrogen, but when pale blue liquid oxygen is poured near the poles of the magnet, it shows definite attraction.

Magnetic Properties |

Atomic Properties / Structure |

Liquids

FerrofluidA magnet placed just below a dish containing ferrofluid generates an array of spikes in the fluid.

Liquids |

Magnetic Properties |

Metals |

Atomic Properties / Structure

Boiling by CoolingA flask contains water and water vapor at 100C. Each time ice water is poured over the outside of the flask, the water inside the flask boils. Although the temperature of the water in the flask has decreased, in each instance boiling is observed.

Gases |

Liquids |

Phases / Phase Transitions / Diagrams

Plastic SulfurYellow powdered sulfur is heated until it becomes molten and brown. At first it flows freely, but then it becomes very viscous. Upon further heating, the viscous sulfur flows freely again and ignites. The burning liquid sulfur is poured into a beaker of water. When removed from the water, the sulfur is rubbery and flexible.

Vapor Pressure: Molecular SizeThe measurement of pressure exerted by a vapor is demonstrated using barometers. Vapor pressure varies with the strength of the intermolecular forces in the liquid.

Gases |

Liquids |

Noncovalent Interactions |

Phases / Phase Transitions / Diagrams |

Physical Properties

Vapor Pressure of a Mixture: Raoult's LawThe measurement of pressure exerted by a vapor is demonstrated using barometers. Vapor pressure varies with the strength of the intermolecular forces in the liquid.
In this section we will look at vapor pressure of mixtures. We can calculate the vapor pressure of a mixture using Raoult's law.

Gases |

Liquids |

Noncovalent Interactions |

Phases / Phase Transitions / Diagrams |

Physical Properties

Piezoelectric EffectSounds accompany the discharges of electricity.
A piezoelectric crystal is connected to a light bulb. When the crystal is pressed, the light flashes.

Hardness of Solid Substances - GrindingA number of metals and nonmetals are ground with a mortar and pestle. The nonmetals shown here are all soft (due to weak intermolecular forces), but the metals vary in hardness.

Covalent Bonding |

Nonmetals |

Physical Properties |

Solids |

Metallic Bonding |

Metals

Thermochromism: Mercury(II) IodideWhen red-orange Mercury(II) Iodide (HgI2) is heated, it undergoes a phase transition at 126oC to a pale yellow form. As the heated sample cools, it gradually returns to the original red-orange color.